1. Field of the Invention
The present invention relates to an image editing method and apparatus for obtaining an image for editing by composing a character image with a low resolution image, and also to an image composing method and apparatus for obtaining a composite image by composing a character image with an original high resolution image.
2. Description of the Related Art
A printing service for printing a composite image has been in practice. In this service, among image data coded hierarchically from low resolution to high resolution, editing operations such as composition with a character image are carried out on the low resolution image data, and this editing procedure on the low resolution image is recorded in an editing description file. This editing description file is transferred to an image server via a network, and processing such as composition with a character image is carried out on the high resolution image according to the procedure by an image composing computer in the image server. A composite image is then printed.
In such a service, when the character image is composed with the low resolution image, the kind of low resolution image, a position at which the character image is inserted, and font information (such as the content of the characters and the size thereof) are recorded in the editing description file. The character image is generated by the image composing computer in the image server using a font of a size suitable for the high resolution image, based on the font information. The character image is then inserted into the high resolution image at the position corresponding to that of the low resolution image, and the composite image is generated as a result. For example, when the low resolution image is an image having a reduction ratio of 1/4 of the high resolution image and the font of the characters inserted in the low resolution image is of 20 point, the image server generates the character image using a font of 20xc3x974=80 point, and inserts the character image in the high resolution image.
However, in a character image composed of x-point characters and having a size of H1xc3x97W1 as shown in FIG. 4(A) and in a character image composed of characters of xxc3x97n point and having a size of H2xc3x97W2, H2/H1=n or W2/W1=n as shown in FIG. 4(B)is not necessarily true. Actually, it is often found that the above relations are not satisfied. This is because a character of a font having a large point number is generated from vector information, while a character of a font having a small point number is pre-stored as an image and not generated from vector information. For example, a 48-point character shown in FIG. 5(a) is different in width, height, and line thickness from a 12-point character magnified by 4 shown in FIG. 5(b). Therefore, if a character image composing a font of a point number in accordance with a magnification between the high and low resolution images is inserted in a high resolution image, the position of the character image is different from an image for editing, and the image to be printed is not in accordance with the image for editing, due to the character image extending beyond the high resolution image, for example.
Furthermore, when characters of a special font are inserted in the low resolution image upon editing, the font may not be supported by the image server. In such a case, the image server cannot compose the character image requested by a user with the high resolution image.
Based on consideration of the above problems, an object of the present invention is to provide an image editing method and apparatus as well as an image composing method and apparatus, for matching up a composite image with an image for editing.
An image editing method of the present invention is an image editing method for carrying out composition of a character image with a low resolution image generated by reducing an original image by a predetermined ratio, and comprises the steps of:
generating an enlarged character image by enlarging the character image based on the predetermined ratio;
generating a reduced character image by reducing the enlarged character image based on the predetermined ratio; and
generating an image for editing by composing the reduced character image with the low resolution image.
xe2x80x9cEnlarging the character image based on the predetermined ratioxe2x80x9d means to enlarge the image by a magnification of n if the predetermined ratio is 1/n.
It is preferable for the image editing method of the present invention to output the enlarged character image and information regarding the low resolution image as an editing description file.
The xe2x80x9cinformation regarding the low resolution imagexe2x80x9d herein referred to means the kind of low resolution image, a position at which the character image is inserted, font information (the content and the size of the characters), and the like.
An image composing method of the present invention obtains a composite image by composing the enlarged character image with the original image, based on the editing description file output by the image editing method of the present invention.
An image editing apparatus of the present invention is an apparatus for carrying out composition of a character image with a low resolution image generated by reducing an original image by a predetermined ratio, and comprises:
enlarged character image generating means for generating an enlarged character image by enlarging the character image based on the predetermined ratio;
reduced character image generating means for generating a reduced character image by reducing the enlarged character image based on the predetermined ratio; and
editing means for generating an image for editing by composing the reduced character image with the low resolution image.
It is preferable for the image editing apparatus of the present invention to further comprise output means for outputting the enlarged character image and information regarding the low resolution image as an editing description file.
An image composing apparatus of the present invention comprises composition means for obtaining a composite image by composing the enlarged character image with the original image, based on the editing description file output by the image editing apparatus of the present invention.
Upon generation of the image for editing through composition of the character image with a low resolution image generated by reducing the original image by the predetermined ratio, the image editing method and apparatus of the present invention enlarges the character image to a size appropriate for the original image, and reduces the enlarged character image by the predetermined ratio to compose the reduced character image with the low resolution image. Since the reduced character image is generated by reducing the enlarged character image by the predetermined ratio corresponding to a ratio between the original image and the low resolution image, a ratio between the width and height of the reduced character image is approximately the same as in the enlarged character image. Therefore, between the image for editing and the composite image obtained by insertion of the enlarged character image with the original image, the ratio of width and height of the character image and the position of the character image are approximately the same and the two images agree.
When the image composition is carried out by using the enlarged character image, the enlarged character image and the information regarding the low resolution image are output as the editing description file, and the composite image is obtained through composition of the enlarged character image with the original image carried out by the image composing method and apparatus of the present invention, based on the editing description file.